Field of the Invention
The present invention relates to an imaging apparatus and particularly relates to processing for recording image data for use in three-dimensional display (hereinafter also referred to as “3D display”) and image data for use in two-dimensional display (hereinafter also referred to as “2D display”) in a file.
Description of the Related Art
In recent years, there has been a rapid increase in the prevalence of devices associated with stereoscopic images such as three-dimensional (3D) cinema, 3D display, or the like. Conventionally, photographing stereoscopic images has been carried out by film cameras or the like. However, with the prevalence of digital imaging apparatuses, photographing original images for generating stereoscopic images using digital cameras, digital video cameras, or the like has become common.
As a mechanism by which a user views a stereoscopic image, data for a right-eye image and a left-eye image with parallax in the left-right direction is prepared so as to correspond to an image of the object viewed with the left eye and an image of the object viewed with the right eye. A user can view stereoscopic images by viewing the right-eye image and the left-eye image with his/her right eye and left eye, respectively. Examples of such a method include a method for dividing a parallax image to be viewed, such as a parallax barrier method, a lenticular method, or the like. Also, a method for providing different images to the left eye and the right eye of a user via a filter having different characteristics between the left and right sides thereof is known.
On the other hand, as a method for capturing an image which is viewable as a stereoscopic image, Japanese Patent Laid-Open No. 58-24105 discloses a method for simultaneously capturing images at different viewpoints. Japanese Patent Laid-Open No. 58-24105 discloses a solid-state imaging element in which a plurality of micro lenses is formed and at least one pair of photodiodes is arranged close to each of the micro lenses. Of the pair of photodiodes, a first image signal is obtained from the output of one photodiode and a second image signal is obtained from the output of the other photodiode. A user can view a stereoscopic image using the first and second image signals as a left-eye image signal and a right-eye image signal, respectively.
Although left-eye image data and right-eye image data can be managed as separate files, the following circumstance may occur for management of image data. In other words, the management of image data as separate files becomes complex as well as a stereoscopic image cannot be viewed if one of the files is lost. Accordingly, in the file generation method disclosed in Japanese Patent Laid-Open No. 2010-200354, left-eye image data and right-eye image data are recorded in the same file, and thus, efficient file management can be realized. In this case, a left-eye image or a right-eye image is used for two-dimensional display, whereas both of a left-eye image and a right-eye image are used for three-dimensional display.
Japanese Patent Laid-Open No. 2008-518317 discloses an output parallax map having an output element which has an output value corresponding to a shift to be applied to each pixel of a first image. A second image can be generated based on the output parallax map and the first image. This calculation is based on an input parallax map having input elements each having an input value and can generate a second image using the input image and the parallax map in order to render a multi-view image.
Assume the case where photographing is performed using the solid-state imaging element disclosed in Japanese Patent Laid-Open No. 58-24105 in which a plurality of micro lenses is formed and at least one pair of photodiodes is arranged close to each of the micro lenses. In the solid-state imaging element, one of a pair of photodiodes outputs a left-eye image signal which is obtained by photoelectrically converting a light flux having passed through a region of an exit pupil of an imaging optical system and the other outputs a right-eye image signal which is obtained by photoelectrically converting a light flux having passed through a region different from the aforementioned region of the exit pupil. In this case, depending on the type of an object, neither the left-eye image nor the right-eye image may be an image reflecting the shape of the object.
For example, in a photographic scene in which light from a point light source is photographed in a blurred manner, a photograph of the light source blurred in a circular pattern should be taken originally. However, when an image is captured by the solid-state imaging element disclosed in Japanese Patent Laid-Open No. 58-24105, the captured image may be in a semicircular or elliptical shape not reflecting the shape of an object. In addition, for example, the shape of the object which is captured as an image is photographed in a different way between the left-eye image and the right-eye image so that the left half of the object in the left-eye image is missing and the right half of the object in the right-eye image is missing. The reason for this is that, among the light fluxes emitted from the exit pupil of the imaging optical system, the region of light received by a photodiode is different along the optical axis serving as the boundary.
Even if such left-eye image data and right-eye image data are generated as one file using the technique disclosed in Japanese Patent Laid-Open No. 2010-200354, the imaging apparatus may display a two-dimensional image having an incorrect shape upon image replay.
In addition, even if there is an attempt to calculate a second image using the technique disclosed in Japanese Patent Laid-Open No. 2008-518317, an image reflecting the correct shape of an object cannot be obtained. In other words, an original image is photographed in a shape different from that of the actual object, and thus, the calculated second image cannot be reproduced as a correct image.
When a parallax map is used, an image file needs to be created in accordance with a file format compatible with a generally-used application. When a file including parallax map data and a file including image data are created separately, a plurality of files needs to be managed. In consideration of the usability of file management by a user, it is preferable that both data are enclosed in a single file.